VAS pain score, IL-6, cortisol, IL-1beta, IL-8, and substance p, height, and weight were checked preoperatively. All ISB were performed preemptively under ultrasonographic guidance. After sterile preparation and draping of the injection area, the structures of the brachial plexus were identified using ultrasound (Sonosite M-Turbo 13 mHz linear probe; Sonosite Corp, Bothell, Washington). Injections were performed using an out-of-plane technique using a plexus needle (Plexus Nano Line Uniplex, 22 gauge, 50 mm; Pajunk Corp, Geisingen, Germany). Nerve stimulation was not conducted.